Sugar cane mill



Y May 9, 1933. A, P. LEONARD 1,908,519

SUGAR CANE MILL Filed July 10, 1928 3 Sheets-Sheet l A. P. LEONARD SUGARCANE MILL May 9, 1933.

Filed July lO, 1928 5 Sheets-Sheet 2 May 9, 1933.

A. P. LEONARD SUGAR 4CANE MILL fmlum Patented May 9,

UNITE-Di STATES" PTENT orifice A'ppiication med Jury 1o,

My invent-ion relates to sugarcane mills and the like andparticularly tocrushing rolls for use therein and to the provisionof means forcollecting andl withdrawing ,from the rolls the maximum quantity of canejuice. An important feature of my invention relates to the removal oftherliquid from the upper le lower rollsis af top roll, which presses downV0 upon the same with enormous force; crushing andmangling the cane into,what is known asbagasse, squeezing"Y out the cane juice, and rising andfalling with variations in thickillness of the matted bagasse. A turnplate is locatedy between the lower rolls to guide the cane from thefeed roll to the bagasseroll and a pan is provided below the rolls tocollect` the expressed. juice. f4.' The pressureof the rolls upontheecane results in the squeezing out of a substantial proportion'of thejuice and the crushing and matting ofi/the fibrous structure of thecane. en compressed between the rolls and turn `Zplate ofthe mill at thehigh pressure commonly used, the blanket of bagasse becomes so denselypacked as to have a structure ,ap-

proaching lthat of wood. The resistance of this densely matted fibrousmaterial to the itz flow ofl juice therethrough is extremely high. 40 Ingrinding at high capacity and with consequently hick blankets of bagasseit is apparent .that muchof thefjuice in the upper strat-a of thebagasse will be yprevented Afrom flowing downward into the pan below andthat the operation of the mill will be rendered ineffectual tol thatextent.

In order to facilitate the collection of the juice which is in the lowerportion of the mat` it has been customary in sugar cane mills of thischaracter to provide the lower 192e. sei-iai No: 291,649.

rolls withdeep circumferential grooves which constitute `openchannelsfor the flow of-.juice i mto the ,pan.` A'lhe'zse grooves greatlyincrease the .efficiency of the mill by effectingthere#r moval vof. agreater proportion of. expressedV juice than is possiblein similar millsnotproi V1 dediwith such grooves. Y An But' no means .has heretoforebeen known so far as I am awarefor facilitating the removalof the juicewhich appears in the upper strata of -theicane or bagasse adjacent thetop roller. This juice being prevented by the density of the mat frompassing downwardly to .the lower rolls large part compelled to remain inthe mat as 165 it passes betweenmthe, pressure. rolls andis at once.reabsorbed by the bagasse upon the removal .of pressurefas the niaterial passes out of the mill.. It. has apparently been thoughtimpossible to provide the top roll with .passages .for the removal kofthe juice as these passages wouldconstitute open channels permittingflow of juicefrom the crushed f cane'at the inlet side ofthe machinetothe bagas'se at the outlet side of machine `thereby 775 in effectshort circuiting the mill. For this reason existing devices areeffectual to only a limited extent and it is necessary topaflss Ythecane through a long series of mills in order to extract .all ofthehj'uice which it is 80 economically possible to obtain from theicane.`Theobjects of this, invention include the` provision of'means forremoving juice exud'e'd from the upper portion'iof the hagas's'e'mat in85" the sugarcane milllthefprovision of lo'ngi tudinal grooves inthetop`roller' both 4for removing juices and'for improving the feed'-` ingeffect ofwsuchf` roller, and in general tof e provide mean'sdlfor4making lsugar cane mills 90" of thistype moreeflcient sothat eachmillcapable vof extracting a greater percentage ofrv expressed juice than,heretoforejand so that a lesser .numberofmills yin seriesis .capable eof extracting'the same or a greater quantity 95 ofjuice. .l i, l Y.Other objects,l novel featuresV and' aldvan-A tages of this inventionwill be apparent from therkfollowing specification and accompanyingdrawings wherein and so to the pan is in 1 Fig. 1 is a vertical sectionthrough one embodiment of the invention.

Fig. 2- is a perspective view of one form of top roller.

Fig. 2-a is a similar view of al modified form of top roller.

Fig. 3 is an end view partially broken away of an embodiment slightlymodified from that of Fig. 1.

Fig. 4 is an enlarged partial section of a roller.

Fig. 5 is a side elevation partly broken away of a modified form ofcrushing roller.

Fig. 6 is an end view thereof, and

Fig. 7 is a section on the line 7-7 of Fig. 5.

The cane mill disclosed in the drawings consists essentially of a toproller 10 mounted on a shaft 11, a feed roller 12 mounted on a shaft 13,a bagasse roller 14 mounted on a shaft 15 and a turn plate 16 mounted ona turn-plate 17. These three rollers are normally geared together andare driven inf such manner that the top roller rotates clockwise asshown in the drawings while the lower rollers rotate countercloclrwise.The surface of these rollers may be serrated or groovedcircumferentially or may be smooth. Bagasse, indicatedat'18, is fed tothe mill by a conveyor 19 and is gripped between the top roller 10 andthe lower rollers 12 and 13 at zones indicated by the reference numerals20 and 21 where it is subjected to enormous pressure which results inthe crushing and mating of the cane and the exuding of a large portionof the juices therein.

Juice exuded from the lower portion of the bagasse mat is removed inthesame manner as heretofore. The bagasse vdrawn between the rollers inf the zone '2O forms av dense mat which is carried through the mill andjuice expressed from the upper portion thereof has a tendency to collectin the zone designated as 22 and unless removed therefrom is reabsorbedby the bagasse. Between the zones 20 and 21 the pressure on the bagasseis somewhat lrelieved and juice exu'ded in the zone 21 tends to collectAin the bagasse mat between zones 20 and 21. Beyond the zone 21 thepressure on' the bagasse isagain relieved and liquid may be suppliedthereto for maceration purposes,if desired.

The upper roller 11 is provided with longitudinal channels 25 whichextend through the end faces ofthe roller and communicate with theactivel surfaceof the roller through slots 26 of less width than thebody ofthe channels. The channels 25 and the` slots 26 are eitherslightly spiral as shown in Fig. 2 orparallel to the axis as shown inFig. 2a. A scraper 27 is provided to contact with the surface of theroller 1() after the latter moves out of contact with the bagasse matand strips froml the roller bagasse adhering thereto. These'channels andslots provide means for draining juice collecting in the zone 22 and inthe bagasse mat between the zones 20 and 2 As the roller 1() rotatesjuice in the zone 22 flows through the slots 26 and into the channels 25by gravity. Upon further rotation of the roller 10 the slots 26 arebridged with bagasse which penetrates to a 4depth approximate equal tothe width of the slots. As each channel approaches the zone 2O juice isforced thereinto through the bagasse bridge under pressure and kthiscondition exists in varying degrees of pressure until after the channelpasses through the zone 21.

At each end of the roller 10 there are provided hoods 28 and 29 whichare stationary but are provided with suitable means for sealing themagainst the ends of the roller. A pipe 30 leads to the hood 28 and apipe 31 leads to the hood 29. The hood 28 is in communication with theends of the channels into which juice flows and collects juice from thechannels 25 and discharges it into the pipe 30 by which it is led to anysuitable collector. If desired the pipe 30 may be connected to a suctionsource to assist in the removal of the juice from the channels.v Meansmay also be provided for connectinng the pipe 30 to a pressure sourcefor introducing air or liquid intothe channels if desired. The juiceiiows into the channels either by gravity or under pressure and isremoved through the hood 28 either by gravity or with the aid ofsuction.

The hood 29 is arranged beyond the pressure zone 21 and liquid maybesupplied thereto through the pipe 31 for delivery to the bagasse matfor maceration purposes. The liquid supplied to these channelsthrough'the hood 29 may also be used to force outof the slots 26 thebagasse vplugs therein. rlhe roller 12 may be provi-ded with `similarchannels and slots asshown in Fig. 1 or may have a 'smooth surface asshown in Fig. 3. When two rollers are provided with the drainagechannels, the latter are so arranged that the channels of one roller areout of register with the channels of the other. Means may also beprovided for applying suction or pressure through the channels in theroller 12. By

this arrangement a high degree of eiiiciency i in the removal of juiceis obtainable. The hoods 28 and 29, while preferable, maybe dispensedwith and the juice be permitted to drop from the ends of the channelsinto the ordinary collecting pans. Y

The longitudinal slots 26 have the further function of assisting thefeeding ofthe bagasse through the mill. In the Vfirst place thesegrooves remove thejuice from the zone 22 and this tends to keep dryerthe bagasse aboutto enter themill insuring good Contact between the toproller and the bagasse thus assisting in feedingthe latter between therollers. The bagasse in contact with the roller penetrates the slots 26to a depth approximately equal to the width ofthe slot and as thepressure increases due to the converging ofthe top and lower rollers thebagasse is thrust firmly into the slots. ln this way the roller llobtains a grip on the bagasse which although local is not confined tothe bagasse from the slots may be effected if felt through aconsiderable zone due to the fibrous nature ofthe bagasse and itstendency to adherence due to the entwining of the libers. After passingthrough the 'mill the bagasse adhering to the rollers is sheared off bythe scraper `27 and any bagasse remaining within the slots is deprivedof its supportingportion so that it may drop down into the channel bygravity or may be pushed by fresh bagasse as the roller rotates. Thechannels diverge sharply from the slots so that no support can beobtained for the loose bagasse from the sides of the channels. Thebagasse which drops into the channels is carried out with the juice. Theremoval of bagasse from the slots may be effected if desired by means ofa drum 32 (Fig. 3) having fins or vanes 33 adapted to project into theslots 26. This drum may be rotated in any suitable manner at properspeed to insert a vane into each slot and thus punch the bagasse intothe channel. The bagasse plugs also may be forced outwardly bymaceration liquid, if used, introduced through the pipe 31 and hood 29into the grooves 25, thus also allowing free egress of the macerationliquid through the slots 26 to the upper surface of the bagasse mat.

The rotation of the top roller lO periodically brings each slot andchannel into the zone 22 and the juice collects in this Zone flows intothe channel through the slots by gravity. As the channel and slot movefrom` the zone 22 to the zone 20 the juice is forced into the channelthrough the slot under pressure, after the groove and slot pass the Zone-20 the pressure is relieved somewhat, but the juice is still forcedthrough the grooves into the channels under pressure until after zone 20is passed and the pressure on the bagasse is relieved. While moving fromthe zone 22 to the zone 21 the channel is in communica- Vtion with thehood 28 and the juice in the channels is drained into the hood either bygravity or by suction. After the zone 2l is passed the channel is incommunication temporarily with the hood 29 and liquid may be suppliedthereto for maceration purpose, and also to push out the bagasse plug.The scraper 27 removes surplus bagasse and should maceration liquid nothave been used, the scraper shears off the projecting portions of thebagasse blocks or tears them out of the slots. The drum 32 ensuresremoval of the bagasse blocks from the slots for the vanes 33 projectinto the slots and positively force any obstruction in the slot into thechannel.

Heretofore it has been necessary to form saryin order to provide asurface which would assist in feeding the bagasse throughr the mill. Inview of the fact that the longitudinal drainage and feeding channels ofthe present invent-ion takes care of the feeding action of therollerwithout the assistance of specially rough and granular roll metal theroller surface may be smooth and polished and may be chilled iron of acomposition which will resist the acids and the mechanical action of thebagasse and which will wear as smooth as possiblein order to producelong roll life.' One of the largest sources of expense in the operationof a cane milling plant as at present constituted consists in thereplacement of the rollshells. Ordinarily such shells yhave to be thrownaway after having been worn down. In view of the fact that withapplicants invention a special metal is not necessary the roller afterit has become worn may be set up in a lathe and metal deposited thereonby means of an electric arc or other welding method lafter which thesurface may be turned down to the desired size.

As before stated the roll surface may be provided with circumferentialshallow grooves or may be provided with longitudinal v grooves extendingparallel with the axis ofthe roller or parallel with the drainagechannels. Moreover if desired the surface of the roller may be given acheckerboard or pyramid surface if desired for certainconditions.

VIn the modification disclosed in Figs. l5, 6

and 7, an upper roller 42 is employed, which roller is provided with aplurality of longitudinal .grooves 44, each groove being tapered fromone end of the roller to the other, so that at one end of the roller thegrooves 44 are deep while at the other end they are relativelyv shallow.In each groove 44 there is provided a bar 46 adapted to slidelongitudinally and radially in the groove. The thicknessv of each bar issuc-h as to fill the groove with only sufficient clearance to ermitsliding of the bar in the groove. ach bar-46 is likewise tapered so thatwhen lying in -its corresponding groove with its tapered edge in contactwith the tapered bottom of the groove the outer edge of the bar eitherlies in the cylindrical surface of the roller or parallel to thatsurface. The bars 46 eX- tend at one end through flange 48 of the toproll into contact with a cam surface 50which controls the movement ofthe bars relative to the roller 42. The bars may cooperate with the camsurface in any desired manner. vAs herein shown each bar 46 is providedwith a notch 52 adapted to fit over the cam surface 50 so thatlongitudinal movement of the bars ree in each direction is controlled bythe cam. The bars which are adjacent the lower poi'- tion of the rollerare moved by the cam surface O-longitudinally toward the deep end of'the groove thereby ypermitting radial movement of the bars toward thecenter of the roll. lThe bars at the side and top of the roller aremoved longitudinally in the opposite direction by the cam surface 50 sothat by force of the wedging action of the tapered surface of the barsand grooves their outer edges approach the outer cylindrical surface ofthe roller. The cam surface 50 may be supported in any desired manner asby lugs A54 attached to the frame upon which the top roller issupported.

The operation of this modification is as follows: As the top rollerrotates and each bar 46' approaches the crushing Zone it is ,drawnlongitudinally with respect to its groove and by reason of'its taper ispermitted to move at the same time radially inward, thereby producing anopen channel running longitudinally of the roll, the outer edges of thebars forming the bottom of the channel.

The crushing process forces juice and bagasse from the top of the matinto the channel so form-ed, the bagasse bridging over the channel andthe juice flowing into it under enormous pressure.v The juice is thenpermitted to flow longitudinally of the roller throughV the passages andescape through spaces 55 Vand 56 in the flanges 48 and 58. respectivelyof the top roller. Any appropriate means may beprovided for collectingand withdrawing the juice which is thus forced out at the end of the toproller. As the top i'oller rotates further and` the bar emerges fromthecrushing Zone it is moved longitudinally by the cam surface 50 and bywe dging action it is moved at the same time radially outward, therebyscraping the sides of the groove and forcing out any bagasse which hasadhered to the groove. Thus when the bar in question rotates once moreinto the crushing zone and moves endwise and radially to form an outletpassage for the juice, as described, the outlet passage is clean andfree of bagasse and effective for the purpose desired'. Y

. In this last modification as well as in the formeronc bagasse isforced into the grooves provided in the surface of the top roller andassist the latter to obtain a grip on the bagasse mat. In this way theroller obtains a grip on the bagasse which although local is notconfined to the bagasse in the grooves but its feeding force is feltthrough a considerable zone due to the fibrous nature of the bagasse andits tendency toward adhering due tothe intertwining of the fibres.Likewise the grooves 44 constitutes channels through which juicecollected in the region 22 is enabled to quickly drain off and thus tendto dry the bagasse about to enter the mill.

parting from my invention as defined in the appended claims.

I claimzl. A sugar cane mill having a plurality of rollers adapteddirectly to engage bagasse supplied thereto at least one of which isprovided with substantially full length longitudinally extending narrowslots communieating with channelsof greater width and having dischargeopenings at each end of the roller to conduct the uice expressed from'the cane, said slots being adapted to receive bagasse by means of whichthe feeding action ofthe roller is increased.

2. A sugar cane mill having a plurality of rollers adapted directly toengage bagasse supplied thereto at least one of which is provided withsubstantially full length longitudinally extending slots -communicatingwith channels having discharge openings at each end to conduct the juiceexpressed from the cane, said slots being adapted to receive bagasse bymeans of which the feeding action of the roller is increased andmechanical Imeans to effect removal of bagasse from said slots. Y j

3. A sugar cane mill having a plurality of rollers adapted directly toengage bagasse supplied thereto at least one of which is provided withsubstantially full length longitudinally extending narrourslotscommunicating with channels of greater width and having dischargeopenings at each end of the roller to conduct the juice expressed fromthe cane, said slots being adapted to receive bagasse by means of whichthe feeding action of the roller is increased and circumferentialgrooves traversing said slots.

5L.. A sugar cane mill having a plurality of rollers adapted directly toengagehbagasse supplied thereto at least one of which is provided withsubstantially full length longitudinally Xtending slots communicatingwith channels having discharge openings at each end of the roller toconduct the juice expressed froin the cane, said slots being adapted toreceive bagasse by means of which the feeding action of the roller isincreased and means to effect removal of bagasse from said slots andcircumferential grooves traversing said slots.

5. A sugar cane mill having a plurality of rollers adapted directly toengage bagasse supplied thereto at least one of which is provided withlongitudinally extending channels having narrow slots opening onto thesurface of the roller for removing juice expressed from the cane and forreceiving plugs of bagasse to assist in feeding the bagasse mat throughthe mill and means for forming the bagasse plugs through said slots intosaid channels.

6. A sugar cane mill having a plurality of rollers adapted directly toengage bagasse supplied thereto at least one of which is provided withfull length longitudinally extending channels having narrow slotsopening onto the surface of the roller for removing juice expressed fromthe cane and for receiving plugs of bagasse to assist in feeding thebagasse mat through the mill and drainage means communicating with bothends of said channels.

7. A sugar cane mill having a plurality of rollers adapted directly toengage bagasse supplied thereto at least one of which is provided withfull length longitudinally extending channels having narrow slotsopening onto the surface of the roller for removing juice expressed fromthe cane and for receiving plugs of bagasse to assist in feeding thebagasse mat through the mill, means for forcing the bagasse plugsthrough said slots into said channels and drainage means communicatingwith both ends of said channels.

8. A sugar cane mill comprising a feed roller, a discharge roller, a toproller disposed in triangular arrangement therewith, said top rollerbeing provided with full length longitudinal slots arranged at intervalsin its surface for receiving of bagasse to assist in feeding the bagassemat through said mill, said slots communicating with channels of greaterwidth and having discharge openings at each end of the roller.

9. A sugar cane mill comprising a feed roller, a discharge roller, a toproller` disposed in triangular arrangement therewith,` said top rollerbeing provided with longitudinal slots at intervals in its surfaceforming channels to conduct away the juice expressed from the cane, saidslots being adapted to receive bagasse plugs to assist in feeding thesame through the mill, and means for forcing said bagasse plugs inwardlythrough said slots.

10. A sugar cane mill comprising a feed roller, a. discharge roller, atop roller disposed in triangular arrangement therewith, said top rollerbeing provided with longitudinal slots at intervals in its surfaceforming channels to conduct away the juice expressed from the cane, saidslots being adapted to receive bagasse plugs to assist in feeding thesame through the mill, means for forcing said bagasse plugs inwardlythrough said slots and drainage means communicating with both ends ofsaid slots.

11. A sugar cane mill comprising a feed roller, a discharge roller, atop roller disposed in triangular relationship therewith, said toproller having full length longitudinal channels provided with narrowslots leading to the surface of the roller, and means communicating withboth ends of said channels for connecting the same with a pressure orvacuum source. v

l2. A sugar cane mill comprising superposed horizontal crushing rollers,the upper roller being provided with longitudinal drainage channels openat both ends of the roller communicating with the roller surface throughnarrow slots for removing juice extracted from the upper strata ofbagasse blanket.

13. A sugar cane mill comprisinga feed roller, a discharge roller, a toproller disposed in triangular relationship thereto, said top rollerbeing provided at intervals in its surface with slots parallel to theaxis of the roller for receiving bagasse plugs to assist j in feedingthe bagasse blanket through saidy mill, and channels communicating withsaid slots, said channels being of greater width than said slots andhaving discharge openings at both ends of the roller.

In testimony whereof, I have signed my name to this specication.

ALBERT P. LEONARD.

onnnrtenrn or eonnnoTIoN.

Patent No. 1,908,519. May 9, 1933.

ALBERT P. LnoNARo.

it is hereby certied that error appears in the printed specification ofthe above numbered patent requiring correction as follows: Page 2, line92, for "conneetinng" read "conneotng"; page 3, line 6, strike out thewords "from the sie-ts may be effected if" and insert instead "in theslots ont its feeding force si; page 5, line 81, eiairn i2, before"bagasse" insert the word "the"; and that the said Letters Patent shouldbe read with these eorreetions therein that the same may conform to therecord of the case in the Patent fice.

Signed and sealed this 8th day of August, A. D. 1933.

M. J. Moore.

(Seal) Acting Commissioner of Patents.

